The present invention relates to a laser irradiating system, and in particular, to a simplified type laser irradiating system using a rod lens and for irradiating a laser beam in fan-like shape.
A laser irradiating system is used for the purpose of forming a reference plane in building and construction work and civil engineering work. As a simplified type laser irradiating system, a laser irradiating system is known, which uses a rod lens and forms a reference line and a reference plane by irradiating a fan-shaped laser beam. The laser irradiating system as described above is a simplified type laser irradiating system used for the purpose such as room interior finishing work. The irradiating unit can be rotated or the laser irradiating system itself can be rotated so that the irradiation position can be shifted to cope with the working position.
Description will be given on a conventional type laser irradiating system referring to FIG. 10 and FIG. 11.
A base unit 2 is mounted on a leveling base 1, and a housing 4 is rotatably mounted on the base unit 2 via bearings 3.
The leveling base 1 comprises a pedestal 5 and three leveling screws 6. By turning the leveling screws 6 at adequate positions, horizontal positioning of the base unit 2 can be carried out.
A laser beam irradiating unit 7 is provided inside the housing 4. The laser beam irradiating unit 7 has an irradiation optical axis 8 perpendicularly crossing a rotation axis of the housing 4, and the laser beam irradiating unit 7 comprises a light emitting source 9 such as a diode laser for emitting a laser beam 13 on the irradiation beam optical axis 8, a collimator lens 11 for turning the laser beam 13 emitted from the light emitting source 9 to a parallel beam, and a rod lens 12 having an optical axis perpendicularly crossing an optical axis of the collimator lens 11 and perpendicularly crossing the rotation axis of the housing 4.
The laser beam 13 emitted from the light emitting source 9 is turned to a parallel beam by the collimator lens 11. The laser beam 13 is then spread in a horizontal direction by the rod lens 12 and is irradiated through a light projecting window 14 of the housing 4. To facilitate the explanation, the laser beam 13 is shown by spreading it in an up-to-bottom direction in FIG. 10.
The laser beam 13 is spread in a horizontal direction and is irradiated as a fan-shaped laser beam, and forms a horizontal reference plane. A spreading angle of the laser beam 13 is about 100°. When the working position is deviated from the horizontal reference plane, the housing 4 is manually rotated as appropriate. That is, by rotating the housing 4, a horizontal reference plane formed by the laser beam for total circumference can be obtained.
In the laser irradiating system as described above, the reference line and the horizontal reference plane formed by the laser irradiating system must be shifted with the progress of the work. In the conventional type laser irradiating system used in the past, an operator must go back to the laser irradiating system each time the working position is changed, and the housing 4 is rotated and the irradiating position is shifted. In this connection, working efficiency is not very high, and heavier burden is also applied on the operator.
Regarding the accuracy of the horizontal reference plane, angular error must be within about 10 seconds. In the conventional type laser irradiating system as described above, the housing 4 is mounted on the base unit 2 via the bearings 3. The bearings 3 itself have shakiness because of its rotating function. For this reason, when the housing 4 is rotated, a rotation axis is often deviated. Oscillation occurs on the housing 4, and this leads to the oscillation of the horizontal reference plane, which is formed by the laser beam 13 irradiated from the housing 4. Thus, there has been such problem that it is difficult to maintain accuracy for the horizontal reference plane.